A solution contains `Fe^(2+), Fe^(3+)` and `T^(-)` ions. This solution was treated with iodine at `35^(@)C. E^(@)` for `Fe^(3+), Fe^(2+)` is `0.77 V` and `E^(@)` for `I_(2)//2I^(-)` = 0.536 V. The favourable redox reaction is:

Options

A. `I_(2)` will be reduced to `I^(-)`
B. There will be no redox reaction
C. `I^(-)` will be oxidized to `I_(2)`
D. `Fe^(2+)` will be oxidised to `Fe^(3+)`

Answer

C

Explanation

The reaction will take place for which `E_(cell)^(@)` is positive.
(a) `I_(2)+2e^(-)to2I^(-),E_(red)^(@)=0.536V`
`Fe^(2+)toFe^(3+)+e^(-),E_(o x )^(@)=-0.770V`
`thereforeE_(cell)^(@)` will be -ve.
(b) Redox reaction will occur.
(c) `2I^(-)toI_(2)+2e^(-),E_(o x)^(@)=0.536V`
`underline(" "Fe^(3+)+e^(-)toFe^(2+),E_(red)^(@)=+0.770V" ")`
`2Fe^(3+)+2I^(-)to2Fe^(2+)+I_(2),E_(cell)^(@)=+0.164V`
Thus, `E_(cell)^(@)` is +ve. hence, this reaction will occur.
(d). also will not occur.